I was having similar issues and here's what helped me immensely:
Go to Nvidia Control Panel > Manage 3D Settings > Program Settings tab (second tab on the right) > Select/Add TitanFall, scroll down to Power management Mode and set it to
Prefer maximum performance
That right there was a night and day difference for me. Not sure if it will work for you but it's worth a try. The next thing that finished off my tweak and was a tremendous help in locking down 60 FPS for me was unparking my cores using the application in this Tweak Guide:
http://www.pcgamer.com/2014/03/15/t...best-settings-to-maximize-your-effectiveness/
It's extremely simple to use and made a world of difference. Anyone who hasn't tried it and are running multiple cores should look into that. Titanfall/Source games are extremely CPU dependent, so unparking the cores Windows for some reason keeps parked is really good for games like Titanfall.